Effects of selenium on physiological characteristics, selenium content and quality of garlic

A pot experiment was used to investigate the effects of Se on physiological characteristics, Se content and quality of garlic (Allium sativum L. cv. Golden garlic 3) by spraying sodium selenite on leaves of garlic. The results show that physiological characteristics, Se content and quality of garlic are influenced by spraying three concentrations (5, 10 and 15 mg/L) of sodium selenite with different times (1, 2 and 3 times) on April 5th, 15th and 25th. Compared with CK, the photosynthetic pigment content and photosynthetic capacity of the leaves by spraying 2 times of 10mg/L sodium selenite solution are increased effectively, the quality of bolts and bulbs are improved significantly, the fresh weights per bolt and per bulb are increased by 68.25% and 29.00%, and the contents of soluble sugar, soluble protein and vitamin C in bolts and bulbs are increased by 73.05%, 104.66%, 18.95% and 82.01%, 51.27%, 69.82%, respectively. Moreover, the free amino acid content in bulbs is higher (about 138.91% of CK bulbs) than that in CK bulbs, while the free amino acid content in bolts is lower (about 63.05% of CK bolts) than that in CK bolts, and the allicin contents in bolts and bulbs are reduced. We also find that in all the treatment, Se contents in bolts and bulbs are enhanced significantly with application dosage and time of Se, the highest values are 3.85 and 4.41 times of those in CK, respectively. In our experiment, we conclude that the quality of garlic can be improved effectively by spraying 10mg/L Se for 2 times on garlic leaves.